In the Yongjin oilfield of southern Junggar Basin, many wells have been drilled to produce industrial oils. Based on the analysis of fluid inclusions in the reservoirs, in combination with the geological and thermal e...In the Yongjin oilfield of southern Junggar Basin, many wells have been drilled to produce industrial oils. Based on the analysis of fluid inclusions in the reservoirs, in combination with the geological and thermal evolution, the charge history in this area has been studied. The results indicate that the Jurassic Formation and Cretaceous Formation reservoirs contain abundant oil and gas inclusions, and four types of fluid inclusions have been distinguished. According to the homogenization temperatures of the fluid inclusions, the hydrocarbons charged the Cretaceous Formation for two periods, one ranges from the Late Cretaceous period to the Eogene period, and the other ranges from the Neocene period to the present. The oil filling history is correlated with the oil source correlation analysis, which is controlled by the movement of the Che-Mo plaeo uplift. Overall, oil accumulation is characterized by the superposition of two sets of source rocks for two stages in the Shawan depression.展开更多
Based on the comprehensive research on core samples,well testing data and fluid parameters of the reservoirs,the depositional architecture of the abnormal low pressure compartment and fluid characteristics of Huatugou...Based on the comprehensive research on core samples,well testing data and fluid parameters of the reservoirs,the depositional architecture of the abnormal low pressure compartment and fluid characteristics of Huatugou oilfield of Qaidam basin were reported,and the correlation between the compartment and hydrocarbon accumulation was revealed. The result indicates that the reservoirs are located展开更多
There are many problems associated with coiled tubing drilling operations, such as great circulation pressure loss inside pipe, difficulties in weight on bit(WOB) transferring, and high probability of differential sti...There are many problems associated with coiled tubing drilling operations, such as great circulation pressure loss inside pipe, difficulties in weight on bit(WOB) transferring, and high probability of differential sticking. Aiming at these problems, solids-free brine drilling fluid system was developed on the basis of formulation optimization with brine base fluid experiment, which was evaluated and applied to field drilling. Based on the optimization of flow pattern regulator, salt-resisting filtrate reducer, high performance lubricant and bit cleaner, the basic formula of the solids-free brine drilling fluid system was formed: brine +(0.1%-0.2%) Na OH +(0.2%-0.4%) HT-XC +(2.0%-3.0%) YLJ-1 +(0.5%-2.0%) SDNR +(1.0%-2.5%) FT-1 A +(1.0%-5.0%) SD-505 + compound salt density regulator. Lab evaluation showed that the fluid had satisfactory temperature resistance(up to 150 ℃), excellent cuttings tolerance(up to 25%), and strong inhibition(92.7% cuttings recovery); Moreover, its lubrication performance was similar to that of all oil-based drilling fluid. The wellbore could be fairly cleaned at annular up-flow velocity of more than 0.8 m/s if the ratio of yield point to plastic viscosity was kept above 0.5. This fluid system has been applied in the drilling of three coiled tubing sidetracking wells in the Liaohe Oilfield, during which the system was stable and easy to adjust, resulting in excellent cuttings transportation, high ROP, regular hole size, and no down hole accidents. In summary, the solids-free brine drilling fluid system can meet the technical requirements of coiled tubing drilling.展开更多
基金financially supported by the National Basic Research Program(2006CB202300)National Natural Science Foundation of China(41172130)
文摘In the Yongjin oilfield of southern Junggar Basin, many wells have been drilled to produce industrial oils. Based on the analysis of fluid inclusions in the reservoirs, in combination with the geological and thermal evolution, the charge history in this area has been studied. The results indicate that the Jurassic Formation and Cretaceous Formation reservoirs contain abundant oil and gas inclusions, and four types of fluid inclusions have been distinguished. According to the homogenization temperatures of the fluid inclusions, the hydrocarbons charged the Cretaceous Formation for two periods, one ranges from the Late Cretaceous period to the Eogene period, and the other ranges from the Neocene period to the present. The oil filling history is correlated with the oil source correlation analysis, which is controlled by the movement of the Che-Mo plaeo uplift. Overall, oil accumulation is characterized by the superposition of two sets of source rocks for two stages in the Shawan depression.
文摘Based on the comprehensive research on core samples,well testing data and fluid parameters of the reservoirs,the depositional architecture of the abnormal low pressure compartment and fluid characteristics of Huatugou oilfield of Qaidam basin were reported,and the correlation between the compartment and hydrocarbon accumulation was revealed. The result indicates that the reservoirs are located
基金Supported by the China National Science and Technology Major Project(2016ZX05020-004)
文摘There are many problems associated with coiled tubing drilling operations, such as great circulation pressure loss inside pipe, difficulties in weight on bit(WOB) transferring, and high probability of differential sticking. Aiming at these problems, solids-free brine drilling fluid system was developed on the basis of formulation optimization with brine base fluid experiment, which was evaluated and applied to field drilling. Based on the optimization of flow pattern regulator, salt-resisting filtrate reducer, high performance lubricant and bit cleaner, the basic formula of the solids-free brine drilling fluid system was formed: brine +(0.1%-0.2%) Na OH +(0.2%-0.4%) HT-XC +(2.0%-3.0%) YLJ-1 +(0.5%-2.0%) SDNR +(1.0%-2.5%) FT-1 A +(1.0%-5.0%) SD-505 + compound salt density regulator. Lab evaluation showed that the fluid had satisfactory temperature resistance(up to 150 ℃), excellent cuttings tolerance(up to 25%), and strong inhibition(92.7% cuttings recovery); Moreover, its lubrication performance was similar to that of all oil-based drilling fluid. The wellbore could be fairly cleaned at annular up-flow velocity of more than 0.8 m/s if the ratio of yield point to plastic viscosity was kept above 0.5. This fluid system has been applied in the drilling of three coiled tubing sidetracking wells in the Liaohe Oilfield, during which the system was stable and easy to adjust, resulting in excellent cuttings transportation, high ROP, regular hole size, and no down hole accidents. In summary, the solids-free brine drilling fluid system can meet the technical requirements of coiled tubing drilling.
